Since a seat pad used for seats and chairs provided on vehicles such as cars, ships, and aircrafts is demanded to have a cushioning property as well as a vibration absorbing property, synthetic resin flexible foam such as flexible urethane foam is used. However, since the flexible foam has a low air permeability, sweat coming from a person who takes a seat is prone to cause a sweaty feeling. Therefore, there is a seat pad in which a hole is formed, which is penetrated through a pad main body made of flexible foam in the thickness direction, and a three-dimensional mesh-like body is fit into the hole (Patent Literature 1). In the technique disclosed in Patent Literature 1, the three-dimensional mesh-like body is formed of a plurality of three-dimensionally entangled fibers, so that the air permeability of the seat pad in the thickness direction is secured using the three-dimensional mesh-like body, and a sweaty feeling experienced by a person who takes a seat can be suppressed.